Patents by Inventor Atsushi Umeda

Atsushi Umeda has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5719760
    Abstract: To directly mount a generator to an engine block without causing overheating of the generator or a rectifier, a voltage regulator incorporates a rectifier which employs monocrystalline silicon carbide (SIC) MOS power transistors as semiconductor rectifying devices. This voltage regulator is fixed to housings of a generator, and the housings of the generator are directly mounted to an engine block. In this construction, it is possible to prevent overheating of the rectifier in the voltage regulator as well as of armature windings and a field coil of the generator regardless of an increase in the amount of heat transferred to the generator due to direct mounting.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: February 17, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Atsushi Umeda, Makoto Taniguchi, Shin Kusase
  • Patent number: 5719486
    Abstract: A generating apparatus includes a generator, a first and a second rectifiers, and a voltage regulator. The generator has three-phase star-connected armature windings which generate three-phase high-output voltage at phase-terminals and low-output voltage at a neutral point. The first rectifier is a three-phase full-wave rectifier connected between the phase-winding and a high-voltage load, and the second rectifier is a diode connected between the neutral point and a low-voltage load with a battery. The regulator regulates the high output voltage to energize the high-voltage load and, at the same time, the low-output voltage to become an optimum voltage level for charging battery. MOSFETs may be used for the first rectifier to short-circuit the armature windings thereby supplying them with leading currents which are respectively ahead of the high-output voltages, so as to increase the generator output power.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: February 17, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Makoto Taniguchi, Atsushi Umeda, Shin Kusase
  • Patent number: 5708352
    Abstract: An alternating current generator for motor vehicles having an extremely small power loss and which can be simply cooled includes a power converter having at least either high side semiconductor power elements or low side semiconductor elements. The high side power elements connect an output terminal of the armature coil to a high potential terminal of the battery; the low side semiconductor power elements connect an output terminal of the armature coil to a low potential terminal of the battery. The power converter converts the alternating current generated voltage of the armature coil into a direct current voltage to supply electricity to the battery. An exciting current controller includes a switching transistor for controlling an exciting current to a field coil. The semiconductor power elements in the power converter and/or the switching transistor in the exciting current controller are/is formed of SiC material, which is a compound of Si and C, having a resistivity smaller than that of pure Si.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: January 13, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Atsushi Umeda, Masatoshi Togawa, Junji Kawai, Hirohide Sato, Norihito Tokura
  • Patent number: 5694311
    Abstract: A power supply system has a three-phase alternating current generator, a storage battery, and a three-phase rectifying device connected between the alternating current generator and the storage battery. The rectifying device includes three SiC-MOSFETS which are turned on when the corresponding alternating voltage is positive and turned off when the corresponding alternating voltage is negative. A duty control device switches each of the three SiC-MOSFETS on and off according to a selected duty ratio so that the alternating current generator can generate an optimum voltage in proportion to a rotational speed of a rotor of the alternating current generator.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: December 2, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Atsushi Umeda, Makoto Taniguchi, Shin Kusase
  • Patent number: 5691590
    Abstract: In an alternator for a vehicle having a field coil for generating rotating magnetic field and stator coils for generating alternating current voltages in response to the rotating magnetic field, the stator coils are grouped and wound in a dual winding system. In order to reduce magnetic noise, a first group of coils are provided in contact with a stator core and the second group coils. The first and second group of coils are shifted from each other by .pi./3 radian in electrical angle.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 25, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Junji Kawai, Atsushi Umeda
  • Patent number: 5655485
    Abstract: A rotary electric machine such as an alternator or a motor has an engine-cooling water-pump in an integral unit. The rotary electric machine is composed of a frame secured to a front surface of an engine, an electric machine unit , a pump unit and a driving unit. The frame has a wall portion and a water passage formed on a rear surface of the wall portion and connected between the engine cooling system and the engine. The electric machine unit has a stator disposed in thermal contact with a front surface of the wall portion and a rotor fixed to a shaft of the driving unit. The pump unit is fixed to the frame and has a pump impeller disposed in the water passage to take cooling water from the cooling system to the engine through the cooling water passage. The driving member includes a pulley driven by an engine and a shaft supported by the wall portion through a bearing to drive the rotor and the impeller.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: August 12, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shin Kusase, Atsushi Umeda
  • Patent number: 5608616
    Abstract: A power converter for an AC generator for motor vehicles for converting a generated voltage of the AC generator driven by an engine into a DC voltage to feed to a battery includes at least either high-side MOS power transistors for connecting an output end of an armature coil which generates the generated voltage of the AC generator with a high potential end of a battery or low-side MOS power transistors for connecting the output end of the armature coil with a low potential end of the battery. The MOS power transistors each has a source region, a well region and a drain region. A high resistance connected with either a parasitic diode on the side connected with the source generated between the source region and well region or a parasitic diode on the side connected with the drain generated between the drain region and well region in parallel is formed in the MOS power transistors.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: March 4, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Atsushi Umeda, Norihito Tokura, Hirohide Sato
  • Patent number: 5568583
    Abstract: The present invention is intended to provide a dispersion compensating optical fiber for wavelength division multiplex optical communication. A refractive index distribution of the dispersion compensating optical fiber is set to be W-shaped, an outside of a core is formed as an internal clad layer and the outside of the internal clad layer is formed as an outermost clad layer made of pure silica. Germanium for raising the refractive index by 2.8% in a specific refractive index difference is doped in the core, and fluorine is uniformly doped in the internal clad layer so that the refractive index is reduced by 0.45% in the specific refractive index difference. A diameter ratio of the core and the internal clad layer is set to be in a range of 1:1.5 to 1:4.0, a wavelength dispersion slope is set to be in a negative area, and dispersion is controlled to a negative high dispersion structure of -100 ps/km-nm or under.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: October 22, 1996
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Youichi Akasaka, Ryuichi Sugizaki, Atsushi Umeda, Kunio Kokura
  • Patent number: 5550457
    Abstract: An electric power generating device including an induction type electric rotating machine rotating in interlock with an engine comprises an inverter connected at the AC side to and end of an armature winding and at the DC side to an electric power storing device, a detecting means for detecting the quantity of state related to the electric power generating voltage of the induction type electric rotating machine excluding the measured RPM of the induction type electric rotating machine but including the electric power storing voltage of the electric power storing device, and an electric power generation controlling means for maintaining the electric power storing voltage within the preset range by controlling the frequency of the controlling voltage of the inverter based on the quantity of state related to the electric power generating voltage.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: August 27, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shin Kusase, Kenzo Mitani, Atsushi Umeda, Hirohide Sato
  • Patent number: 5543703
    Abstract: A vehicular generator motor performing generator operation and motor operation is disclosed. The generator motor comprises an AC-DC converter means and a switching means. The converter means is composed of a plurality of MOSFETs and connected between each armature coil and a vehicular storage battery. Alternating current produced across the coils is converted into a direct current for charging the battery by the AC-DC converter means in generator operation mode. In motor operation mode, the DC output from the battery is converted into an alternating current for setting up a rotating magnetic field by the converter means, and the battery output is fed to the armature coils. The mode of operation of the MOSFETs is switched between these two modes by the switching means. The rotating field produces a certain phase difference with the magnetic field developed by the rotating magnetic poles. The MOSFETs are made of SiC having a smaller resistivity than that of Si.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: August 6, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shin Kusase, Kenzo Mitani, Atsushi Umeda, Norihito Tokura, Hirohide Sato
  • Patent number: 5536987
    Abstract: An alternating current generator for a motor vehicle includes magnet type field cores, i.e., field cores with claw poles on which permanent magnets are interposed in the spaces between the claw poles, where the generator has a ratio of number of claw poles/outside diameter of the field core that allows generation of a large output current. The alternating current generator includes permanent magnets disposed in spaces between peripherally adjacent claws which reduce the magnetic flux leakage caused by the field coil occurring in the spaces. When a residual magnetic flux density higher than 0.25 tesla is applied in advance in a direction that reduces magnetic flux, a large output current is obtained when the above-noted ratio is in the range of from about 1.6.times.10.sup.-1 to 2.0.times.10.sup.-1 (1/mm).
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: July 16, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Seiji Hayashi, Atsushi Umeda, Shin Kusase
  • Patent number: 5483116
    Abstract: The present invention prevents the degradation of the power generating efficiency of an alternating current generator by preventing the expansion of an air gap formed between pole cores and a stator core, achieves low-noise operation by preventing generation of high-frequency impact magnetic noise, and makes it possible to relieve strains applied on a magnet holder. The present invention utilizes sixteen magnets, each of which fits between two of sixteen claw-like magnetic poles formed on the outer periphery of Lundell-type pole cores, which rotates integrally with a shaft. The magnets are caught and stopped by a magnet holder which has been formed by interconnecting zig-zagging segments and has elasticity as a whole. Here, the permanent magnets are held by the magnet holder so that the magnet holder does not protrude towards the rotor side from the outer peripheral face of the Lundell-type pole cores and the contacting faces of the magnet holder contact the outer faces of the permanent magnets.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: January 9, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shin Kusase, Atsushi Umeda, Saburo Hukaya, Noriyasu Inomata, Hitoshi Irie, Hiroshi Ishida
  • Patent number: 5449962
    Abstract: A stator coil of a rotary electric machine includes a three-phase Y-form connection circuit including first windings Y1, Y2 and Y3, which are connected in Y-form, and a three-phase delta-form connection circuit including second windings .increment.x3, .increment.y3 and .increment.z3 which are connected in delta-form, wherein the second windings .increment.x3, .increment.y3 and .increment.z3 are sequentially inserted in slots of a stator core to have a phase difference of 120.degree. therebetween, and each of the first windings Y1, Y2 and Y3 is divided into two windings, and the divided first windings are separately inserted in the slots, in which the second windings .increment.x3, .increment.y3 and .increment.z3 have been inserted, so that the resultant composite voltage vector of each pair of the divided first windings is shifted by 30.degree. in phase from the voltage vector of one of the second windings .increment.x3, .increment.y3 and .increment.z3.
    Type: Grant
    Filed: October 13, 1993
    Date of Patent: September 12, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventors: Akiya Shichijyo, Shin Kusase, Hiroaki Kajiura, Atsushi Umeda